CLIP-170 is essential for MTOC repositioning during T cell activation by regulating dynein localisation on the cell surface

Sci Rep. 2018 Nov 28;8(1):17447. doi: 10.1038/s41598-018-35593-z.

Abstract

The microtubule-organizing centre (MTOC) is repositioned to the centre of the contacted cell surface, the immunological synapse, during T cell activation. However, our understanding of its molecular mechanism remains limited. Here, we found that the microtubule plus-end tracking cytoplasmic linker protein 170 (CLIP-170) plays a novel role in MTOC repositioning using fluorescence imaging. Inhibition of CLIP-170 phosphorylation impaired both MTOC repositioning and interleukin-2 (IL-2) expression. T cell stimulation induced some fraction of dynein to colocalise with CLIP-170 and undergo plus-end tracking. Concurrently, it increased dynein in minus-end-directed movement. It also increased dynein relocation to the centre of the contact surface. Dynein not colocalised with CLIP-170 showed both an immobile state and minus-end-directed movement at a velocity in good agreement with the velocity of MTOC repositioning, which suggests that dynein at the immunological synapse may pull the microtubules and the MTOC. Although CLIP-170 is phosphorylated by AMP-activated protein kinase (AMPK) irrespective of stimulation, phosphorylated CLIP-170 is essential for dynein recruitment to plus-end tracking and for dynein relocation. This indicates that dynein relocation results from coexistence of plus-end- and minus-end-directed translocation. In conclusion, CLIP-170 plays an indispensable role in MTOC repositioning and full activation of T cells by regulating dynein localisation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Cell Membrane / metabolism
  • Dyneins / metabolism*
  • Humans
  • Immunological Synapses
  • Lymphocyte Activation / genetics*
  • Lymphocyte Activation / immunology*
  • Microtubule-Associated Proteins / genetics*
  • Microtubule-Associated Proteins / metabolism
  • Microtubule-Organizing Center / immunology*
  • Microtubule-Organizing Center / metabolism*
  • Neoplasm Proteins / genetics*
  • Neoplasm Proteins / metabolism
  • Protein Transport
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / metabolism*

Substances

  • Microtubule-Associated Proteins
  • Neoplasm Proteins
  • cytoplasmic linker protein 170
  • Dyneins